A sleeve bearing assembly for opposite ends of a vertical motor each have a lubricant reservoir (16) formed by a high temperature resistant lubricant absorbed into a felt pad. An oil seal (40, 50) of a high temperature resistant rubber is located below each bearing within an annular wall (15) that extends axially of the motor shaft (2). Wings (41 to 44) on the oil seal project into grooves (31 to 34) in the wall to prevent rotation of the seal. Each seal has an annular nib (46 and 47, 51 and 52) at each end that engage the shaft, forming a rotational seal which impedes downward flow of lubricant along the shaft. A groove (48, 53, 54) extends coaxially around one or both of the nibs to increase its flexibility.